Hi guys - I've just bought my daughter her first car - A MK4 2003 Gold 1.6L - Have to say I love it. I have a 5 year newer NZ New Suzuki Swift and find myself wanting to drive my daughters car on quick trips. Its comfortable - Has heated seats and the heater gets warm WAYYY quicker than the Swift.

We've got two issues at present.

1. OIL SENSOR WORKSHOP error message on starting the car - I've done a full oil change with high quality Castrol Edge 0w30 and the error stopped for one or two starts but its back again. I'm picking its a faulty sensor so I may or may not change that next time I'm doing an oil change - I've seen I can pickup cheap ones from Aliexpress and as far as I can tell it only does Oil Level and I'm happy to check that the old fashioned way.

Please correct me if my assumptions / limited research are wrong here

2. We are losing a little coolant - We are seeing it on the driveway, its dripping from the front of the engine itself down onto the plastic tray and then onto the driveway. I gave everything a good wipe and clean to help see where its dripping. To me its either from the engine block itself or from around a plastic "plug". I suspect the latter. Basically there are the various plastic hose attachments that fit to the engine block/head (I'm not terribly auto-mechanical - I do the basic oil change and brake pads), there is also what looks to be just a plastic plug in one of these holes in the engine. I'm guessing its plugging a hole that is an optional cooling hose spot for something this car doesn't have. Does anyone know what I'm talking about - Its on the left side only about 8 inches from middle of the engine from memory (I'm at work now). I can take some photos and come back and add them but I'm hoping someone will know what I'm talking about.

I had milky white residue on the oil filler cap which freaked me out but some more reading online indicates this alone is common due to condensation etc so I've cleaned it off to see if I get more. The oil that I changed was black but a good consistency with no milky fouling and checking the dipstick since the change its nice and clean/clear so I'm hoping its not a head gasket.

Its a 2003 with 186,000Km on the clock (I read somewhere VW don't consider these engines High Mileage until 500K?) and I paid 2500 for it in Auckland and had family drive it down. Seems like a pretty reasonable deal so far but won't seem so good if its in for a head gasket change. I think if I take of the radiator cap and run the engine I should look for air bubbles to confirm if its head gasket?

I have to say I'm dead keen to get a VW golf for the next family car as I'm so impressed with the build quality of this car - Problem is we tow a caravan so I've either got to have a tow car just for that or maybe invest in a Touareg to get the best of both worlds?

This picture shows the plastic part I suspect might be leaking. As it doesn't have any hoses or wires for sensors so I suspect it covers a hole that a hose would exit on different optioned engine models?

This shows the pool of coolant sitting on the edge of the engine block/head. It doesn't look like its coming where the head meets the block, its sitting above the lip where the two meet.

Update. It's all fixed. I took it to our local, Burgess Automotive who if you are in the Christchurch Northwest are brilliant. I've always found their billing very reasonable. They pressure checked it, confirmed it was leaking from that plastic plug. He took it out to inspect the seal and said it was cracked and perishing on the inside so ordered a new one and fitted and re-pressure tested and it's all sealed. Cost $115 which for pressure test, a $25 part and freight charge from Akl and labour is pretty good.